Hollow grate bar assembly



' Oct. 2, 1951 J B HOLLOW CRATE BAR ASSEMBLY Filed July 18, 1947 IN VENTOR ATTORNEYS.

Patented Oct. 2, 1951 i.

o-FFlcs HOLLOW GRATE BAR ASSEMBLY Josef Batik, Prague, Czechoslovakia.

Application July 18, 1947, Serial No. 761,922 In Czechoslovakia January zs, 1947 I The present invention relates to improvements in natural draught grates, grate bars or gratedraught, are each positioned in open grooves,

each bar forming with the respective groove outlet gaps through which an additional or auxiliary combustion medium is supplied to the fuel.

The main advantage of the invention consists in that the arrangement of the aforementioned grooves in connection with existing grate bars permits, even without any other modification of the grate bars themselves, to secure in addition to the natural draught an artificial draught so as to supply, according to requirements, a cur-- rent of compressed air or of pure oxygen, or of some combustible gases, such as are obtained by volatilization of liquid fuels or the like, to assist in securing complete combustion of the solid fuel on the grate. In this arrangement the ashes are free to fall down into the ask pan as in ordinary grates.

Thus the construction of the invention permits a better utilization and improvement of the standard grate structures both in domestic fire places and in industrial furnaces of all .kinds, where complicated constructions have been necessary heretofore in order to enhance the. heating effect, such as automatic devices for feeding the fuel, removing the ashes etc.

The introduction of the simple arrangement according to the present invention permits obtaining a number of advantages in ordinary natural draught grates, such as substantial acceleration of the ignition, permitting ignition by means of ordinary gas, particularly in domestic stoves, also the possibility of using combustible gases for mixed solid fuel and gas heating. By supplying a suitably preheated combustion medium directly to the incandescent zone of the fire place the combustion temperature is increased and the entire combustion process is improved. The formation of soot and smoke may be completely eliminated. According to requirements it is further possible to moderate the draught and thus to reduce the losses or to secure a better utilization of the heat energy.

The device in accordance with the present invention enables moreover satisfactory utilization of fuels of lower grade on standard grates. The controlled supply of auxiliary combustion medium permits easy adjustment of the heating effact according to the need at any moment, this 2 Claims. (Cl. 110-74) feature" being of particular'importance in con-. nection with automatically controlled industrial furnaces.

The grate bars mounted in the grooves through which "the additional or auxiliary combustion medium is supplied," are cooled by such medium and thus are protected against excessive heating, the combustion medium, on the other hand, being advantageously preheated. With the device of the present invention it is thus also possible to burn on otherwise standard grates in domestic, use, for instance, coke and'to suppress the formation of smoke. Finally, an advantage" of particular importance consistsin that when introducing fuel through'the open door of a stove or furnace provided with a grate in accordance with the present invention the temperature fall in the combustion space is reduced.

A simple form of the grate according to this invention isshown by way, of example in the accompanying' drawing, in which Fig. 1 is a partial, sectional view on the line l -l ofFig. 2, showing the'invention applied to a cast iron grate, Fig. 2 isaplan view of the grate with some of the grate bars removed,

Fig. 3 is a, partial [axial longitudinal section and partial side elevation of one of the grate bars,and

Fig. 4 is a section on the line 4--4 of"-Fig."2.

The grate proper consists of grate bars I on which the solid fuel is carried, the ashes falling down into the ash pan through openings 2 (Fig. 2). Beneath the grate bars there are located hollow rib members 3, e. g. of sheet metal, which are formed in part like the elements of radiator bodies for central heating. These members are shown in cross-section in the left hand part of Fig. 1. However, the upper portions of the members are open and the walls 4 of each member form a groove 4', the lower portions of the grate bars I being arranged to project into, and engage with, said grooves 4'. The members 3 are terminated at either end with heads, like the aforementioned radiators, and the heads 5 are passed over tubes 6, the assembly being held together by means of nuts 1. The parts 3 to I form an undergrate structure, located underneath the grate bars of the fire place. The

radiator like construction permits to use standard parts in assembling the auxiliary grate.

The walls 4 of the grooves 4' have embossed projections 8 at their upper edges, and the sides of the grate bars which engage in the grooves 4' bear against said projections. In this way gaps 9 are formed between the sides of the grate bars I and the walls 4 of grooves 4, close beneath the upper surface of the grate, but in such a manner that the ash which falls down from the grate through the openings 2 cannot enter the gaps 9.

The tubes 6 serve to supply, in the direction of arrow l0, an additional or auxiliary combustion medium, :such as air from a fan, or a suitable compressed gas from apressure container. The auxiliary medium flows through the openings ll into members 3, and through the gaps 9 is supplied to the fuel on the main grate, as shown by the arrows I2. The projections 8 are arranged at a closer spacing towards the heads 5, "while their 1 spacing is greater in the intermediate part of the bodies 3, whereby uniform supply ;of the auxiliary medium throughout the length of members 3 is secured. The medium passing out through I gaps 9 prevents the ashes from entering the gaps, should such tendency ariseim spite of -the described arrangement. If necessary, further suitable provisions may be made to prevent access of ashes to the gaps 9.

The form of grate as shown and described is one (of a plurality of possible constructions. Of course, the invention is not restricted to this form and may be appliedin various modifications as required by the purpose and kind of any particular fire place.

In practical use the invention permits to increase the .heat generated on the grate, with automatic increase of the cooling effect of the air on the grate bar-s, up to the heat resistance limit 0-1" the material of the gratebars, and also allows to establish in the most suitable parts .of the fire place different .zones of controllable pressure according to the requirements. A combination is also possible of the described arrangement with an automatic fuel feeding mechanism, the grate 4 What I claim is: 1. A grate comprising a plurality of elongated grate bars disposed in parallel spaced relation to form a fuel bed support with spaces between I the bars for natural draft and the discharge of for the upward discharge of gaseous combustion medium supplied under pressure to said hollow ribs, said inwardly raised portions being disposed closer together adjacent the ends of the ribs thanin the remainder of the length thereof to effect even distribution of gaseous medium throughout the length of said :clischarge slots.

2. A grate bar assembly according to claim .1 in which a plurality of said hollow ribs forming the undergrate structure are connected at the ends thereof to :form a header communicating with each of them for the common supply of gaseous medium thereto.

JOSEF BATI'K.

REFERENCES CITED :Ihe following references are of record in the file of this patent: 

